Process and device for producing clutch friction plate

ABSTRACT

A process for producing a clutch friction plate in which a plurality of friction material segments are bonded to an annular flat face of an annular core plate so that oil channels are formed between the segments, the process including: a step of forming a plurality of strip-shaped friction materials by cutting a band-shaped friction material along its longitudinal direction; a step of aligning and holding portions, corresponding to the segments, of leading edge parts of the materials in positions above the core plate while positioning the portions in the peripheral direction and in the direction along one diameter of the core plate; a step of forming the segments by cutting off the leading edge parts of the materials positioned above the core plate along a cutting-off line that includes at least an arc line that follows the outer periphery of the core plate, and a step of pressing and bonding the segments onto the face coated with an adhesive.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an improvement of a process and adevice for producing a clutch friction plate by bonding a plurality offriction material segments to an annular flat face of an annular coreplate so that oil channels are formed between the friction materialsegments.

2. Background Art

Conventionally, for production of this type of friction plate, anarrangement in which a plurality of friction material segments obtainedby cutting a band-shaped friction material at intervals in itslongitudinal direction are bonded to an annular core plate (e.g.,Japanese Patent Publication No. 4-68491) and an arrangement in which aplurality of friction material segments obtained by punching out from aband-shaped friction material are bonded to an annular core plate (e.g.,Japanese Patent Publication No. 4-68494) are known.

However, in the arrangement disclosed in Japanese Patent Publication No.4-68491, the friction material segments are obtained by cutting them inturn from the leading edge of the band-shaped friction material, whichis fed in a direction along a tangent to the annular core plate, and arethen bonded to the annular core plate, resulting in a low degree offreedom in the shape of the oil channels formed between the frictionmaterial segments. In the arrangement disclosed in Japanese PatentPublication No. 4-68494, the ratio of the area occupied by the frictionmaterial segments so obtained relative to the area of the band-shapedfriction material required, that is, the yield, is low.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the above-mentionedcircumstances, and it is an object thereof to provide a process forproducing a clutch friction plate, the process ensuring a high degree offreedom in the shape of the oil channels and an improved yield in theproduction of the friction material segments, as well as a device forproducing the clutch friction plate, the device being capable ofappropriately carrying out the production process.

In order to attain this object, in accordance with a first aspect of thepresent invention, there is proposed a process for producing a clutchfriction plate by bonding a plurality of friction material segments toan annular flat face of an annular core plate so that oil channels areformed between the friction material segments, the process comprising: astep of forming a plurality of strip-shaped friction materials bycutting a band-shaped friction material along its longitudinal directionwhile feeding the band-shaped friction material in a direction along onediameter of the annular core plate; a step of aligning and holdingportions, corresponding to the friction material segments, of leadingedge parts of the plurality of strip-shaped friction materials inpositions above the annular core plate while positioning the portions inthe peripheral direction and in the direction along said one diameter ofthe annular core plate; a step of forming the plurality of frictionmaterial segments by cutting off the leading edge parts of the pluralityof strip-shaped friction materials positioned above the annular coreplate along a cutting-off line that includes at least an arc line thatfollows the outer periphery of the annular core plate; and a step ofpressing and bonding the plurality of friction material segments ontothe annular flat face coated with an adhesive.

In accordance with this arrangement, the plurality of strip-shapedfriction materials are formed by cutting the band-shaped frictionmaterial in its longitudinal direction, and the portions of the leadingedge parts of these strip-shaped friction materials that correspond tothe friction material segments are cut off at the cutting-off line thatincludes at least the arc line that follows the outer periphery of theannular core plate while the portions are positioned and held in thepositions above the annular core plate so as to form the plurality offriction material segments, which are pressed against and bonded to theannular flat face of the annular core plate coated with an adhesive.Therefore, it is possible to increase the degree of freedom in the widthand shape of the oil channels between the friction material segments,and moreover the production yield of the friction material segments canbe improved.

Furthermore, in accordance with a second aspect of the presentinvention, there is proposed a device for producing a clutch frictionplate by bonding a plurality of friction material segments to an annularflat face of an annular core plate so that oil channels are formedbetween the friction material segments, the device comprising: supportmeans that is capable of positioning and supporting the annular coreplate so that the annular flat face coated with an adhesive faces upwardand the annular core plate can be pivoted intermittently around an axisthereof; a rotating receiving blade that rotates at a fixed position soas to be in contact with a lower face of a band-shaped friction materialextending in a direction along one diameter of the annular core platepositioned and supported by the support means; one rotating round bladeor a plurality of coaxial rotating round blades that rotate so as to bein contact with the outer periphery of the rotating receiving blade andcut the band-shaped friction material along its longitudinal directionto form a plurality of strip-shaped friction materials; a feed rollerthat is in contact from beneath with the plurality of strip-shapedfriction materials in common so as to feed the strip-shaped frictionmaterials toward the annular core plate positioned and supported by thesupport means; a plurality of urethane rollers that rotate so as to beindividually in contact with the upper faces of the strip-shapedfriction materials while sandwiching the strip-shaped friction materialsbetween the urethane rollers and the feed roller; a positioning blockthat aligns and holds portions, corresponding to the friction materialsegments, of leading edge parts of the plurality of strip-shapedfriction materials fed in by the feed roller and the plurality ofurethane rollers in positions above the annular core plate whilepositioning the portions in the peripheral direction and in thedirection along said one diameter of the annular core plate; a cuttingblade that is vertically movable relative to the annular core platepositioned and supported by the support means and has at least an arcpart that follows the outer periphery of the annular core plate; areceiving blade that is fixed to the positioning block in order to cutoff, in cooperation with the cutting blade, the leading edge parts ofthe plurality of strip-shaped friction materials positioned and held bythe positioning block to form the plurality of friction materialsegments; and pressing means that is provided on the cutting blade sothat the plurality of friction material segments cut off by the cuttingblade and the receiving blade can be pressed against the annular flatface of the annular core plate.

In accordance with this arrangement, the plurality of strip-shapedfriction materials are formed by cutting the band-shaped frictionmaterial by means of both the rotating receiving blade which is incontact with the lower face of the band-shaped friction material, andone rotating round blade or the plurality of coaxial rotating roundblades which rotate while being in contact with the outer periphery ofthe rotating receiving blade; the plurality of strip-shaped frictionmaterials thus formed are fed toward the annular core plate by means ofboth the feed roller which is in contact from beneath with thestrip-shaped friction materials in common, and the plurality of urethanerollers which are individually in contact with the upper faces of thestrip-shaped friction materials; the leading edge parts of the pluralityof strip-shaped friction materials positioned and held by thepositioning block in the positions above the annular core plate are cutoff by means of both the cutting blade which moves vertically and has atleast the arc part that follows the outer periphery of the annular coreplate, and the receiving blade mounted on the positioning block, so asto form the plurality of friction material segments; and these frictionmaterial segments are pressed against the annular flat face by means ofthe pressing means provided on the cutting blade. Therefore, it ispossible to appropriately carry out the production process of the firstaspect of the present invention with a simple and inexpensivearrangement while minimizing generation of shaggy cut portions and dustaccompanying the cutting.

The above-mentioned object, other objects, characteristics, andadvantages of the present invention will become apparent from preferredembodiments that will be described in detail below by reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 to FIG. 10 show a first embodiment of the present invention,wherein

FIG. 1 is a plan view of a clutch friction plate,

FIG. 2 is a plan view showing a change of a band-shaped frictionmaterial when producing the clutch friction plate,

FIG. 3 is a diagram showing portions that become scrap after frictionmaterial segments are obtained from the band-shaped friction material,

FIG. 4 is a plan view of a production device for producing the clutchfriction plate,

FIG. 5 is an enlarged sectional view along line 5—5 in FIG. 4,

FIG. 6 is a sectional view along line 6—6 in FIG. 5,

FIG. 7 is a sectional view along line 7—7 in FIG. 4,

FIG. 8 is a diagram showing the shape of a receiving blade,

FIG. 9 is a sectional view, corresponding to FIG. 5, of cutting-offmeans and pressing means in an operating state, and

FIG. 10 is a sectional view, corresponding to FIG. 6, of the cutting-offmeans and the pressing means in the operating state.

FIG. 11 is a diagram showing scrap in a conventional example in whichfriction material segments are obtained by punching out.

FIG. 12 is a plan view of a clutch friction plate of a secondembodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 1, a clutch friction plate 15A is formed by bonding,for example, eight segment groups 19A to each of annular flat faces 16 aon opposite sides of a metal annular core plate 16. The segment group19A includes a triangular friction material segment 17 and fourrectangular friction material segments 18 which are arranged in ananticlockwise direction from the friction material segment 17, each ofthe friction material segments 17 and 18 being made of a fibercomponent, an additive component, a binder component, etc. Oil channels20 are formed between adjacent friction material segments 17 and 18, and18 and 18.

Referring to FIG. 2, when producing the clutch friction plate 15A, onesegment group 19A is simultaneously bonded to the annular flat face 16 aof the annular core plate 16 by carrying out Steps (a) to (d), whichwill be described below. By repeating Steps (a) to (d) eight times, thefriction material segments 17 and 18 are bonded to the annular flat face16 a on one side of the annular core plate 16.

(a) A band-shaped friction material 21 is cut along its longitudinaldirection while being fed in a direction along one diameter of theannular core plate 16 to form a plurality of strip-shaped frictionmaterials 22 and 23. Since one segment group 19A is formed from fivefriction material segments 17 and 18 in the first embodiment, cuttingthe band-shaped friction material 21 at four positions at intervals inthe width direction thereof forms five strip-shaped friction materials22 and 23.

(b) Portions, corresponding to the friction material segments 17 and 18,of leading edge parts of the five strip-shaped friction materials 22 and23 are aligned and held in positions above the annular core plate 16while their positions are fixed in the peripheral direction and in thedirection along said one diameter of the annular core plate 16.

(c) The leading edge parts of the five strip-shaped friction materials22 and 23 positioned above the annular core plate 16 are cut off at acutting-off line 24 which contains at least an arc line 24 a thatfollows the outer periphery of the annular core plate 16, to form thefive friction material segments 17 and 18. In the first embodiment,among the five friction material segments 17 and 18 forming the segmentgroup 19A, the friction material segment 17, which is at one end alongthe peripheral direction of the annular core plate 16, that is, thedirection in which the friction material segments 17 and 18 arearranged, is triangular, and the cutting-off line 24 therefore containsnot only the arc line 24 a but also a straight line 24 b that intersectsthe arc line 24 a.

(d) The five friction material segments 17 and 18 are pressed againstand bonded to the annular flat face 16 a which has been coated with anadhesive.

In accordance with this production process, as shown in FIG. 3, sincethe five friction material segments 17 and 18 forming one segment group19A are formed so that the segment groups 19A are arranged in sequencealong the longitudinal direction of the band-shaped friction material21, and one friction material segment 17 of each of the groups 19A istriangular, portions shown by the intersecting diagonal lines in FIG. 3become scrap 25.

A production device for carrying out the above-mentioned productionprocess is now described. Referring to FIG. 4, this production deviceincludes: support means 28 that can intermittently pivot whilepositioning and supporting the annular core plate 16 in a manner inwhich the annular flat face 16 a coated with an adhesive faces upward;cutting means 29 that cuts the band-shaped friction material 21 whichextends in a direction along one diameter of the annular core plate 16positioned and supported by the support means 28, at for example fourpositions to form five strip-shaped friction materials 22 and 23;feeding means 30 for feeding the strip-shaped friction materials 22 and23 toward the annular core plate 16; a positioning block 31 that holdsthe portions, corresponding to the friction material segments 17 and 18,of the leading edge parts of the five strip-shaped friction materials 22and 23 so as to position the portions in the positions above the annularcore plate 16; cutting-off means 32 that cuts off the leading edge partsof the five strip-shaped friction materials 22 and 23 positioned andheld by the positioning block 31 to form the five friction materialsegments 17 and 18; and pressing means 33 that presses the cut-off fivefriction material segments 17 and 18 against the annular flat face 16 aof the annular core plate 16.

Referring FIG. 5 and FIG. 6 together, the support means 28 includes adisc-shaped support table 36 pivotably supported, via a bearing 35, on abase 34 fixed to the floor, an electric motor 37 supported by the base34 beneath the support table 36 so that the electric motor 37 exhibits adriving force to pivot the support table 36, and a transmissionmechanism 38 provided between the support table 36 and the electricmotor 37 so as to transmit the driving force of the electric motor 37 tothe support table 36 while reducing its speed.

The annular core plate 16 is positioned and supported on the supporttable 36 with the axis of the annular core plate 16 aligning with thepivot axis of the support table 36 so that the annular flat face 16 acoated with an adhesive (not illustrated) faces upward. Operation of theelectric motor 37 is controlled so that the annular core plate 16 ismade to intermittently pivot around its axis. Since eight segment groups19A are bonded to the annular flat face 16 a of the annular core plate16 in the first embodiment, the electric motor 37 is controlled so thatthe annular core plate 16, that is, the support table 36, is pivotedintermittently by 45 degrees each time.

Referring again to FIG. 4, the cutting means 29 includes a rotatingreceiving blade 40 that rotates at a fixed position so as to be incontact with the lower face of the band-shaped friction material 21, andone rotating round blade 41 or a plurality of coaxial rotating roundblades 41 that rotate so as to be in contact with the outer periphery ofthe rotating receiving blade 40 and cut the band-shaped frictionmaterial 21 along its longitudinal direction, thus forming a pluralityof strip-shaped friction materials 22 and 23. Since the fivestrip-shaped friction materials 22 and 23 are formed from theband-shaped friction material 21 in the first embodiment, four coaxiallyrotating round blades 41 rotate so as to be in contact with the outerperiphery of the rotating receiving blade 40.

A rotating shaft 42 of the rotating receiving blade 40 and a commonrotating shaft 43 of the rotating round blades 41 are connected to arotating drive source 44 so that the rotating shaft 42 and the rotatingshaft 43 rotate in opposite directions in synchronism with each other.

The feeding means 30 includes a feed roller 45 that is in contact frombeneath with the strip-shaped friction materials 22 and 23 in common,and a plurality (five in the first embodiment) of urethane rollers 46that rotate individually in contact with upper faces of the strip-shapedfriction materials 22 and 23 while sandwiching the strip-shaped frictionmaterials 22 and 23 between the urethane rollers 46 and the feed roller45. A rotating shaft 47 of the feed roller 45 is rotatably supported bya pair of support plates 49 arranged on opposite sides of thestrip-shaped friction materials 22 and 23, and one end of the rotatingshaft 47 is connected to a drive source 50 mounted in one of the supportplates 49. A common rotating shaft 48 of the urethane rollers 46 isrotatably supported by the support plates 49 so that the urethanerollers 46 rotate by following the strip-shaped friction materials 22and 23 fed by the feed roller 45.

Referring FIG. 7 in addition, the positioning block 31 is disposedbetween the support table 36 and the feeding means 30 so as to overlap apart of the annular core plate 16 on the support table 36, and isspring-biased upward while being capable of ascending and descending ina limited range. That is, a pair of guide tubes 51 are provided so as tostand on the base 34 on opposite sides of the strip-shaped frictionmaterials 22 and 23, upper ends of mating shafts 52 fitted from aboveinto the guide tubes 51 are secured to the positioning block 31, and apair of coil springs 53 surrounding the guide tubes 51 are providedunder compression between the base 34 and the positioning block 31.

Moreover, the pair of support plates 49 supporting the feeding means 30are secured to the positioning block 31, so that the feeding means 30also ascends and descends together with the positioning block 31.

The positioning block 31 integrally includes a block main portion 31 ahaving guide grooves 54 and 55 on a lower face, through which thestrip-shaped friction materials 22 and 23 are inserted, and a protrudingportion 31 b protruding from a lower part of the block main portion 31 atoward the annular support plate 16 on the support table 36. Theprotruding portion 31 b is formed into a comb shape so as to positionthe portions, corresponding to the friction material segments 17 and 18,of the leading edge parts of the strip-shaped friction materials 22 and23 while positioning in the peripheral direction of the annular coreplate 16 and in a direction along one diameter of the annular core plate16. Among the leading edge parts of the strip-shaped friction materials22 and 23, portions protruding toward the annular core plate 16 from theguide grooves 54 and 55 of the block main portion 31 asituate atpositions fixed by the protruding portion 31 b in the peripheraldirection of the annular core plate 16 and in the direction along saidone diameter of the annular core plate 16.

Movement of the strip-shaped friction materials 22 and 23 along thelongitudinal direction thereof is stopped while the strip-shapedfriction materials 22 and 23 are positioned by the protruding portion 31b of the positioning block 31, and during this process the feed roller45 of the feeding means 30 rotates idle.

A sliding-contact projection 31 c, which is in resilient sliding contactwith a cam 56 disposed above the block main portion 31 a, isprojectingly provided at the upper end of the block main portion 31 a ofthe positioning block 31, and a rotating shaft 57 of the cam 56 isconnected to a rotating drive source 58. The cam 56 is thus rotated bythe rotating drive source 58, and the block main portion 31 a, that is,the positioning block 31, ascends and descends accompanying the rotationof the cam 56. The rotating drive source 58 is mounted in a supportframe 59 fixed to the base 34 on opposite sides of the positioning block31.

The cutting-off means 32 includes a cutting blade 60 and a receivingblade 61. The cutting blade 60 can move vertically relative to theannular core plate 16 positioned and supported on the support table 36of the support means 28, and has at least an arc part 60 a that followsthe outer periphery of the annular core plate 16. The receiving blade 61is fixed to the positioning block 31 so that the receiving blade 61, incooperation with the cutting blade 60, cuts off the leading edge partsof the strip-shaped friction materials 22 and 23 positioned and held bythe positioning block 31 to form the five friction material segments 17and 18.

The cutting blade 60 is supported on the positioning block 31 so that itis vertically movable relative to the positioning block 31. A space forallowing the cutting blade 60 to move vertically is formed between theblock main portion 31 a and the protruding portion 31 b of thepositioning block 31. Furthermore, in the first embodiment, the cuttingblade 60 having at least the arc part 60 a that follows the outerperiphery of the annular core plate 16 includes not only the arc part 60a but also a straight line part 60 b that intersects the arc part 60 abecause, among the five friction material segments 17 and 18 forming thesegment group 19A, the friction material segment 17 at one end in theperipheral direction of the annular core plate 16, that is, in thedirection in which the friction material segments 17 and 18 arearranged, is triangular. On the other hand, the receiving blade 61 isformed as shown in FIG. 8 so as to correspond to the shape of thecutting blade 60, and is fixed to a lower face of the block main portion31 a so as to block from below the guide grooves 54 and 55 on the lowerface of the block main portion 31 a of the positioning block 31.

A lower end of a connecting rod 63 extending upward is pivotablyconnected to the cutting-off means 32 having the cutting blade 60, andan upper end of the connecting rod 63 is pivotably connected to therotating shaft 57 of the cam 56 at a position that is eccentric withrespect to the rotational axis of the rotating shaft 57. The cuttingblade 60 therefore moves vertically accompanying rotation of the cam 56,so that the positioning block 31, the receiving blade 61, and thecutting blade 60 can be raised and lowered by the common rotating drivesource 58 while the cutting blade 60 can move vertically relative to thepositioning block 31 and the receiving blade 61.

The pressing means 33 is formed from a plurality of pressing projections64 and 65 integrally provided with the cutting blade 60 so as tocorrespond to the friction material segments 17 and 18 respectively,which are to be bonded to the annular core plate 16. The pressingprojections 64 and 65 are formed into a shape such that they areinserted from above into the protruding portion 31 b of the positioningblock 31 when the cutting blade 60 moves downward relative to thepositioning block 31.

When the triangular friction material segment 17 is cut off from theleading edge part of the strip-shaped friction material 22 by means ofthe cutting blade 60 and the receiving blade 61, the triangular scrap 25is generated. An opening 67 is provided in a portion of the protrudingportion 31 b corresponding to this scrap, and the cutting blade 60 isprovided with a sweeping-out member 66 for sweeping the scrap 25remaining on an upper face of the receiving blade 61 outward via theopening 67.

Movements of the positioning block 31, the cutting-off means 32, and thepressing means 33 are described with reference to FIG. 9 and FIG. 10.The strip-shaped friction materials 22 and 23 fed by the feeding means30 are positioned and held by the positioning block 31, which is presentat a relatively high position as shown in FIG. 5 and FIG. 7, and arethen moved directly above the annular core plate 16 on the support table36 as the positioning block 31 descends. Subsequently, the cutting blade60 moves downward relative to the positioning block 31, thereby cuttingoff the friction material segments 17 and 18 from the leading edge partsof the strip-shaped friction materials 22 and 23 by means of the cuttingblade 60 and the receiving blade 61. When the cutting blade 60 thenfurther descends as shown in FIG. 9 and FIG. 10, the friction materialsegments 17 and 18 are pressed downward by the pressing projections 64and 65 of the pressing means 33 while being guided by the positioningblock 31 and the receiving blade 61, and pressed against the annularflat face 16 a of the annular core plate 16, which has been coated withan adhesive.

The operation of the first embodiment is now described. When theplurality of, for example five, friction material segments 17 and 18 arebonded to the annular flat face 16 a of the annular core plate 16 sothat the oil channels 20 are formed between the friction materialsegments 17 and 18, and between 18 and 18, the band-shaped frictionmaterial 21 is cut in its longitudinal direction to form the pluralityof, for example five, strip-shaped friction materials 22 and 23;portions, corresponding to the friction material segments 17 and 18, ofthe leading edge parts of the strip-shaped friction materials 22 and 23are cut off at the cutting-off line 24 that contains at least the arcline 24 a that follows the outer periphery of the annular core plate 16(the cutting-off line 24 containing the arc line 24 a and the straightline 24 b in the first embodiment) while the portions are positioned andheld in the positions above the annular core plate 16 to form theplurality of, for example five, friction material segments 17 and 18;and the friction material segments 17 and 18 are pressed against andbonded to the annular flat face 16 a of the annular core plate 16, whichhas been coated with an adhesive.

In accordance with such a production process, in comparison with aconventional arrangement in which friction material segments obtained bycutting in sequence from the leading edge part of the band-shapedfriction material 21 fed in a direction along a tangent to the annularcore plate 16 are bonded to the annular core plate 16, the degree offreedom in the width and shape of the oil channels 20 between thefriction material segments 17 and 18, and between 18 and 18 can beincreased.

Furthermore, in a conventional arrangement in which a plurality offriction material segments obtained by punching out the band-shapedfriction material 21 are bonded to the annular core plate 16, as shownin FIG. 11, a large amount of scrap 70 is generated after the punchingout, whereas in the first embodiment as shown in FIG. 3 only the scrap25 having a small area is generated, thus improving the production yieldof the friction material segments 17 and 18.

Moreover, in the production device for producing the clutch frictionplate 15A, the band-shaped friction material 21 is cut by means of boththe rotating receiving blade 40 which is in contact with the lower faceof the band-shaped friction material 21, and one rotating round blade 41or a plurality (four in the first embodiment) of coaxial rotating roundblades 41 which rotate so as to be in contact with the outer peripheryof the rotating receiving blade 40, thus forming the plurality ofstrip-shaped friction materials 22 and 23; the plurality of strip-shapedfriction materials 22 and 23 thus formed are fed toward the annular coreplate 16 by means of both the feed roller 45 which is in contact frombeneath with the strip-shaped friction materials 22 and 23 in common,and the plurality (five in the first embodiment) of urethane rollers 46which rotate in individual contact with the upper faces of thestrip-shaped friction materials 22 and 23; the leading edge parts of theplurality of strip-shaped friction materials 22 and 23 positioned andheld in the positions above the annular core plate 16 by the positioningblock 31 are cut off by means of both the cutting blade 60 which movesvertically and has at least the arc part 60 a that follows the outerperiphery of the annular core plate 16 (the cutting blade 60 containingthe arc part 60 a and the straight line part 60 b in the firstembodiment), and the receiving blade 61 mounted on the positioning block31, thus forming the plurality of friction material segments 17 and 18;and these friction material segments 17 and 18 are pressed against theannular flat face 16 a by the pressing means 33 provided on the cuttingblade 60.

In this way, the rotating receiving blade 40 and the rotating roundblades 41 are used when the strip-shaped friction materials 22 and 23are formed by cutting the band-shaped friction material 21, and thecutting blade 60 and the receiving blade 61 are used when the frictionmaterial segments 17 and 18 are cut off from the leading edge parts ofthe strip-shaped friction materials 22 and 23. Therefore, it is possibleto minimize generation of shaggy cut portions and dust accompanying thecutting, and to appropriately carry out the above-mentioned productionprocess with a simple and inexpensive arrangement as compared with anarrangement employing a punching-out die.

FIG. 12 shows a second embodiment of the present invention. A clutchfriction plate 15B is formed by bonding, to annular flat faces 16 a onopposite sides of a metal annular core plate 16, for example, tensegment groups 19B each containing a plurality of, for example five,friction material segments 18 having an identical shape and beingparallel to each other so that oil channels 20 are formed betweenadjacent friction material segments 18 of each group 19B and triangularoil channels 68 are formed between the groups 19B.

In accordance with this second embodiment, the cutting-off line usedwhen cutting off the friction material segments 18 from fivestrip-shaped friction materials may contain only an arc line, thearrangement of cutting-off means 32 in the production device can befurther simplified, and moreover no scrap is generated, thus increasingthe yield to 100%.

Although embodiments of the present invention have been described indetail above, the present invention is not limited to theabove-mentioned embodiments and can be modified in a variety of wayswithout departing from the subject matter of the present invention.

1. A process for producing a clutch friction plate by bonding aplurality of friction material segments to an annular flat face of anannular core plate so that oil channels are formed between the frictionmaterial segments, the process comprising: a step of forming a pluralityof strip-shaped friction materials by cutting a band-shaped frictionmaterial along its longitudinal direction while feeding the band-shapedfriction material in a direction along one diameter of the annular coreplate; a step of aligning and holding portions, corresponding to thefriction material segments, of leading edge parts of the plurality ofstrip-shaped friction materials in positions above the annular coreplate while positioning the portions in the peripheral direction and inthe direction along said one diameter of the annular core plate; a stepof forming the plurality of friction material segments by cutting offthe leading edge parts of the plurality of strip-shaped frictionmaterials positioned above the annular core plate along a cutting-offline that includes at least an arc line that follows the outer peripheryof the annular core plate; and a step of pressing and bonding theplurality of friction material segments onto the annular flat facecoated with an adhesive.
 2. A device for producing a clutch frictionplate by bonding a plurality of friction material segments to an annularflat face of an annular core plate so that oil channels are formedbetween the friction material segments, the device comprising: supportmeans that is capable of positioning and supporting the annular coreplate so that the annular flat face coated with an adhesive faces upwardand the annular core plate can be pivoted intermittently around an axisthereof; a rotating receiving blade that rotates at a fixed position soas to be in contact with a lower face of a band-shaped friction materialextending in a direction along one diameter of the annular core platepositioned and supported by the support means; one rotating round bladeor a plurality of coaxial rotating round blades that rotate so as to bein contact with the outer periphery of the rotating receiving blade andcut the band-shaped friction material along its longitudinal directionto form a plurality of strip-shaped friction materials; a feed rollerthat is in contact from beneath with the plurality of strip-shapedfriction materials in common so as to feed the strip-shaped frictionmaterials toward the annular core plate positioned and supported by thesupport means; a plurality of urethane rollers that rotate so as to beindividually in contact with the upper faces of the strip-shapedfriction materials while sandwiching the strip-shaped friction materialsbetween the urethane rollers and the feed roller; a positioning blockthat aligns and holds portions, corresponding to the friction materialsegments, of leading edge parts of the plurality of strip-shapedfriction materials fed in by the feed roller and the plurality ofurethane rollers in positions above the annular core plate whilepositioning the portions in the peripheral direction and in thedirection along said one diameter of the annular core plate; a cuttingblade that is vertically movable relative to the annular core platepositioned and supported by the support means and has at least an arcpart that follows the outer periphery of the annular core plate; areceiving blade that is fixed to the positioning block in order to cutoff, in cooperation with the cutting blade, the leading edge parts ofthe plurality of strip-shaped friction materials positioned and held bythe positioning block to form the plurality of friction materialsegments; and pressing means that is provided on the cutting blade sothat the plurality of friction material segments cut off by the cuttingblade and the receiving blade can be pressed against the annular flatface of the annular core plate.